darry wrote on 2023-09-08, 06:30:

RetroPC_King wrote on 2023-09-08, 04:53:

I also got a VGA to HDMI adapter, that works even on 720x400 and 320x200, and also a HDMI capture stick. Also the old VGA-HDMI adapter I had (that broke, the problem was yellow tint on image and blue channel was absent) didn't supported 720x400 and 320x200 video modes. Now with the new VGA-HDMI adapter I can capture old DOS games and see the PC BIOS.

Does it convert 70Hz to 60Hz or pass it through as is ?

Can you share a link ( or at least some keywords that one can use to find it) to where you got it from ?

I don't know if it's converting 70 Hz to 60Hz or if pass it thorugh as is, but it works. Also, this adapter (1st picture, the new one) I got it from some Romanian marketplace. Try to find VGA to HDMI adapter as keywords.

mrfusion92 wrote on 2023-09-08, 06:38:

RetroPC_King wrote on 2023-09-08, 04:53:

I also got a VGA to HDMI adapter, that works even on 720x400 and 320x200, and also a HDMI capture stick.

I hope you are more lucky than me with that capture stick, two broke on me because they overheat very much.

Yes. I am lucky with that capture stick, it doesn't overheat very much, it is warm or hot sometimes, but not too hot to be untouchable, but it works. I am satisfied with it.

Hello all!
I just bought a DSC-301-HD for a decent price and I wonder if the output will be sharper than my RGB-HDMI-300-a, has anyone compared the two?
For reference, I'm using the 300-a to capture my 486 PC VGA output (using a ezcap Gamedock Ultra as the capture device)
I also have a Gefen ext-vgaaud-2-hdmis and the image quality is spectacular, but it has some really annoying notification when the resolution changes that can't be turned off.
Any thoughts?

I had no luck at all with the cheap sticks, in terms of dos resolutions and frequency. Did the job though for 640*480 and up though in win98,.but I doubt these cheap sticks are the best available option for this purpose.

I picked up an Altona At-500d with version 6.03 firmware. It is happy with dos resolutions and frequencies. Inability to adjust sharpness, and it's as fuzzy as the cheap sticks.

Mine doesn't seem to have the colour issues others have mentioned in this thread. Black is black. Reasonably happy with it.

Dusko wrote on 2023-12-17, 02:25:

Hello all! I just bought a DSC-301-HD for a decent price and I wonder if the output will be sharper than my RGB-HDMI-300-a, has […]
Show full quote

Hello all!
I just bought a DSC-301-HD for a decent price and I wonder if the output will be sharper than my RGB-HDMI-300-a, has anyone compared the two?
For reference, I'm using the 300-a to capture my 486 PC VGA output (using a ezcap Gamedock Ultra as the capture device)
I also have a Gefen ext-vgaaud-2-hdmis and the image quality is spectacular, but it has some really annoying notification when the resolution changes that can't be turned off.
Any thoughts?

Hola - how does your DSC-301-HD compare to the RGB-HDMI-300?

Sorry for the stupid question, I am new to that topic. Is the Extron DVS 304 RGB Scaler a suitable solution to do scaling from 320x200 to a VGA-connected monitor ?

For anyone interested, I was trying to find some of the adapters mentioned earlier in this thread, but most are no longer available. I found one on Amazon from Fantia with the same shape so I thought it may have the same internals. Also tried the Foinnex lookalike version, but that one put a lot of resolutions out of range.

It’s not perfect though. It sometimes gives diagonal interference lines on dark screens just like others mentioned with the Foinnex. Strange that it appears to only do it when at 640x480 60Hz, or in Text Mode. I tried moving the USB supply power from the PC port to a power block on the wall, but didn’t seem to help. If I switch through every other resolution, there is no issue so it’s probably not a power noise issue. Weird thing is that it is sporadic, a few times I was able to start Quake in 640x480 without the lines, but they will show up the next time I switch to that mode.

It seems like it sets the monitor to h=31.3khz v=70hz instead of a real resolution when in DOS text mode or 320x200 game. I can also tell the aspect is not correct. It is stretching a little wider than 4:3 in this mode.

Every single "VGA to HDMI" adapter on Amazon is the cheapest possible crap made by fake shell companies for the same Chinese factories that produce all of them.

Jhonny0099 wrote on 2025-02-24, 01:52:

[...] Strange that it appears to only do it when at 640x480 60Hz, or in Text Mode.

[...]Weird thing is that it is sporadic, a few times I was able to start Quake in 640x480 without the lines, but they will show up the next time I switch to that mode.

My guess about this is that the capture card is slightly misdetecting the genlock (# of clocks per horizontal scanline, or clock rate). This can result in slight aliasing, phase shifting in adjacent pixel brightness/sharpness, or in faint vertical or diagonal lines appearing.

When doing multiple "trials" by reinitializing the video mode, the capture device will attempt to re-lock to the video mode, likely by luck getting a better guess on some times, compared to others.

Getting a very good digital signal sampling from analog VGA requires a device that has clock speed several times the Nyquist frequency, in order to supersample the signal, but also a detailed understanding of the behavior of different VGA adapters and the video modes that they generate. (i.e. VGA borders, and 640 vs 720 clocks per scanline at minimum for the standard modes)

I probably mentioned this before in this thread, the best way to solve the analog->digital conversion problem is to avoid having the problem in the first place: CRT Terminator Digital VGA Feature Card ISA DV1000

Thanks for the info. Yeah it’s probably just a piece of junk, but the first adapter yet that can even display DOS.. I know a few people earlier in this thread also mentioned the Aixxco adapter as one of the few cheap adapters that were decent. Tried to find it by name to buy without any luck.

However, tried using an image search and found a few listings of what appears to be the same device with different brand names on it. Ordered one to give it a shot. If this one doesn’t work, I give up.
https://a.co/d/04QtSDK

I have a VGA input on my monitor, so I can always go back to that and do straight VGA-VGA. Only thing I don’t like about it is that it stretches 720x400 text mode or 320x200 games to widescreen. Preserve Aspect is disabled on the monitor in these modes. Anything 640x480 and above look great in 4:3 using Preserve Aspect.

I also have another machine hooked up to this monitor via DVI and it perfectly scales to 4:3 in all modes. In another thread someone suggested that converting to a digital signal may make it easier for the monitor to detect and retain 4:3. So that’s why I started looking into VGA-HDMI converters for my VGA only machine. I’ll report my findings when the new adapter arrives.

Honestly, for DOS stuff, the CRT Terminator is shaping up to be the best option these days: CRT Terminator Digital VGA Feature Card ISA DV1000

It's no good for anything mid to late Win9x as it won't go above 800x600 256 colors, but it's better than any other VGA to HDMI solution that has yet been found.

Theoretically a truly GOOD VGA to HDMI adapter could be created, but I don't think it's really been done yet. Maybe if you spent $700 on a RetroTink 4K or something, but even then I don't think it's perfect, in the sense of responding to the VGA signal the way a CRT does in real time.

Lots of people seem to say that Extron's products are decent. I'm not a great judge but I think the one I got is okay. I got a tip (I think from this thread) that one can generally find the Extron RGB-DVI cheaper than the RGB-HDMI and I certainly managed to find one on eBay that was cheap enough for me - only about 4x the cost of the Amazon rubbish. Well, if you ignore the fact that in the end some of the Amazon ones I tried ended up being free, after I complained about them not doing what their listings said they did.

Jhonny0099 wrote on 2025-02-24, 01:52:

For anyone interested, I was trying to find some of the adapters mentioned earlier in this thread, but most are no longer availa […]
Show full quote

For anyone interested, I was trying to find some of the adapters mentioned earlier in this thread, but most are no longer available. I found one on Amazon from Fantia with the same shape so I thought it may have the same internals. Also tried the Foinnex lookalike version, but that one put a lot of resolutions out of range.

The attachment IMG_7348.jpeg is no longer available

It’s not perfect though. It sometimes gives diagonal interference lines on dark screens just like others mentioned with the Foinnex. Strange that it appears to only do it when at 640x480 60Hz, or in Text Mode. I tried moving the USB supply power from the PC port to a power block on the wall, but didn’t seem to help. If I switch through every other resolution, there is no issue so it’s probably not a power noise issue. Weird thing is that it is sporadic, a few times I was able to start Quake in 640x480 without the lines, but they will show up the next time I switch to that mode.

It seems like it sets the monitor to h=31.3khz v=70hz instead of a real resolution when in DOS text mode or 320x200 game. I can also tell the aspect is not correct. It is stretching a little wider than 4:3 in this mode.

The attachment IMG_7346.jpeg is no longer available

I used to have one of these to connect my DVB receiver to a very old LCD TV. It fried itself after about 1 month of use. Be wary.

Received an OSSC Pro the other day. With just the right scanline settings, it looks exactly like a CRT with heavy scanlines. Beyond that I can't get it to work very well, as vertical boundaries between pixels on fields of solid colors are highly visible, which detracts from the experience. I can't get it to stop doing that.